The present invention relates to hermetic compressors, and more particularly to draining compressor oil from a hermetic compressor and recharging a hermetic compressor with oil.
In general, lubricating fluid such as oil is removed from a hermetic compressor for any number of reasons. One such reason may be that a sample of the oil is needed for testing to analyze its properties such as viscosity, for example. Additionally, it may be desired to determine the amount of oil located in the compressor housing in comparison to the amount of oil the compressor had been initially charged with, thus determining if there had been any oil loss during compressor operation. By determining the amount of oil located in the compressor housing, one can also ensure that a sufficient amount of oil is available to the compressor components during compressor operation. Further, spent oil may be removed from the compressor housing and replaced with fresh, clean, or a different type of oil.
Conventionally, to drain oil from a hermetic compressor, the compressor must be disconnected and removed from its assembly with a refrigeration system. The suction, discharge, and electrical connections are disconnected and the compressor is removed from the refrigeration system. The oil in the compressor housing is poured from the compressor housing through a drain/fill opening in the housing into a suitable container. After being drained, the compressor may be recharged with oil through the drain/fill opening and reassembled to the refrigeration system.
A problem with this method of draining oil from a hermetic compressor is that the removal of the compressor from its assembly in the refrigeration system is time consuming, labor intensive, and expensive. The removal of the compressor requires stopping refrigerant flow through the suction and discharge lines and then disconnecting the suction line, discharge line, and electrical connections. An additional problem is that refrigerant may leak from the suction and discharge lines as well as from the compressor after being disconnected.
It is desired to provide a method and apparatus for draining oil from and recharging oil into a hermetically sealed compressor without having to remove the compressor from its system.